Question: Christopher starts counting at 49, and he counts by fours. If 49 is the 1st number that Christopher counts. what is the 8th number that he counts?
What is the first number that he counts? $49$ What is the second number that he counts? $\begin{align*}&49 + 4 \\ &= 53\end{align*}$ What is the third number that he counts? $\begin{align*}&49 + 4 + 4 \\ &= 49 + (2 \times 4) \\ &= 57\end{align*}$ What is the 8th number that he counts? $\begin{align*}&49 + (7\times4) \\ &= 49 + 28 \\ &= 77\end{align*}$